Many individuals suffer from allergies triggered by air borne allergens. It would be a benefit to these individuals to have a filter system that could be used to filter out the allergens prior to reaching the nasal passageways. In addition, because there are many social situations where an individual would not wish to call attention to himself by wearing a face mask, it would be a further benefit to have a filter system that included a filter assembly that could be positioned within the nostril of a wearer. It would be a further benefit to have such a filter system with a nostril insertable filter assembly that also included a nose shroud for covering the nose of the wearer and providing additional filtering elements for prefiltering the air prior to reaching the nostril insertable filter assembly for those individuals in a situation where such a cover device would not pose a problem.